EEEP 3/2015


Editor's comment

I. Simeonov            3-4


Lidar detection of forest fire aerosols above Sofia (August 2013)

Atanaska D. Deleva             5-14

Anthropogenic micro-detritus as a factor for cotemporary forming of sediments and soils

Anton Sotirov, Nikola Pistalov, Dana Mawlood, Mihaela Yerusalimova, Siana Savova, Rositsa Vezenkova, Melani Eftimova, Daniel Velinov, Denislav Kirilov        15-21

Spatial and temporal distribution of floods and fires on the territory of Bulgaria, based on MODIS data for the period 2004 2015

Maria Dimitrova, Roumen Nedkov             22-28


Investigation on humus-carbonate soils in the Western Balcan mountains foothill

Simeon Bogdanov, Slavcho Savev, Evgeni Tzavkov          29-35

Ecologycal investigations and protection of forest ecosystems in Vitosha mountain

Nadezhda Stoyanova, Biljana Hristova           36-41


Microbial fuel cells with denitrification system

Tsvetomila I. Parvanova-Mancheva, Venko Beschkov, Evgenia Vasileva           42-46

Comparative study of photovoltaic systems with different types of modules

Zahari Zarkov, Ludmil Stoyanov, Hristiyan Kanchev, Valentin Milenov, Vladimir Lazarov              47-56


Characteristics and evaluation of the sludge from wastewater plant treatment station Kazanlak for use in practice

Svetla Marinova, Nikola Katidjotes,Viktor Kolchakov, Elena Zlatareva,Vera Petrova                57-63

Influence of C/N ratio on anaerobic digestion of cattle manure

Venelin Hubenov, Dencho Denchev, Ivan Simeonov                   64-72



Atanaska D. Deleva

Abstract. Experimental results from remote investigations of atmospheric aerosol loading over Sofia during forest fires from August 2013 are presented in the following work. The measurements are performed by LIDAR (LIght Detection And Ranging) equipped with Nd:YAG laser generating at 1064 nm. Vertical profiles of the aerosol backscatter coefficient are processed and analyzed. Mass temporal evolution and spatial distribution of the registered aerosol layers are illustrated by 2D-colormaps in height-time coordinates. Lidar data shows presence of dense layers not only in the lower troposphere up to height of 3-4 km, but also in the altitude range of 8-1km. It was inferred that the air up to 4 km above Sofia has been loaded/polluted with smoke and other particles emitted by the forest fires occurring close to the city. Additionally, on the basis of HYSPLIT (HYbrid Single-Particle Lagrangian Integrated Trajectory) backward trajectories for the days of measurement it was suggested that air masses high in the troposphere were having mixed composition and part of the aerosols in them were long-distance transported by the raging at the time devastating forest fires in Portugal, Spain and North America.

Key words: lidar, aerosols, fire smoke, troposphere



Anton Sotirov, Nikola Pistalov, Dana Mawlood, Mihaela Yerusalimova, Siana Savova, Rositsa Vezenkova, Melani Eftimova, Daniel Velinov, Denislav Kirilov

Abstract. Aim of the present study is to focus attention on solid anthropologic waste as a factor for cotemporary forming of sediments and soils. As a result of the study various solid micro-detritus was found in river sediment and alluvial soils at place of a former illegal landfill in town of Kyustendil, Bulgaria. Part of organic fragments were distinguished and counted using fluorescence microscopy. It was tried to be applied infrared light for microscope study of the samples and to give term of reference for its possible using with combination with thermo-camera. Percentage and profile of the micro-detritus was done. Connection between contamination of surface water and micro-detritus was established.

Key words: anthropogenic micro-detritus and fragments, soils, sediments, contamination


Spatial and temporal distribution of floods and fires on the territory of Bulgaria, based on MODIS data for the period 2004 2015

Maria Dimitrova, Roumen Nedkov

Abstract: In this paper we present spatial and temporal distribution of significant floods, land and forest fires on the territory of Bulgaria during a period from June 2004 till the end of April 2015. Events were recognized using data from radio-spectrometer with medium spatial resolution (MODIS) on the satellite platforms Terra and Aqua. A specialized web-database of composite images with a spatial resolution of 250 meters in the visible and near infrared range from MODIS for each day of the period is built. 251 days with floods and 96 days with land or forest fires were observed. Vector layers are generated with attributive information, which includes the location, duration and area of occurrence of each event. An analysis and results were obtained for the spatial and temporal distribution of floods and fires on the territory of Bulgaria.

Key words: eco monitoring, floods, land and forest fires.



Simeon Bogdanov, Slavcho Savev, Evgeni Tzavkov

Abstract. The paper presents results from investigation on soils located in the southern area of the Western Balcan Mountains foothill. Humus-Carbonate soils (Rendzinas) have been investigated. They are situated in the Middle forestry zone (6001800 m a.s.l.) of the Misian forestry area. Soil samples have been taken for three years from six soil profiles. The study covers area of 2000 m2. The factors of soil formation have been characterized. Soil physical and chemical properties have been investigated. The results are processed by statistical programme. The arithmetical averages and variation coefficients have been calculated.

Key words: humus-carbonate soils, factors of soil formation, physical properties, chemical properties



Nadezhda Stoyanova, Biljana Hristova

Abstract: The article presents the main research activity of the Forest Research Institute at BAS on ecolgy and conservation of forest ecosystems in Vitosha Mountain since 1980. This study is motivated by the importance of Vitosha forests for environmental improvement of Sofia region. The short review shows that investigations  at the Forest Research Institute covers various aspects in the field of ecology and biology of the forests. Climatic conditions are characterized. Data of health state of forest ecosystems are established. The study obtained information about soil conditions and regeneration processes in the forests. The results may be useful for the sustainable management of forest ecosystems of Vitosha Mountain.

Key words: ecology, climate, forest ecosystems, state



Tsvetomila I. Parvanova-Mancheva, Venko Beschkov, Evgenia Vasileva

Abstract. Microbial fuel cells (MFC) offer a novel approach in the field of wastewater treatment, which can generate electricity through degradation of the substrates containing nitrates.

Nitrate and nitrite have been a worldwide groundwater contaminant mainly due to the use of fertilizers, industrial wastes, animal wastes and septic systems. High concentrations of nitrate and nitrite in drinking water can cause several health problems such as blue baby syndrome for infants, and also can lead to liver damage and cancer in adults.

Microbial production of electricity may become an important form of bioenergy in future because MFCs offer the possibility of extracting electric current from a wide range of soluble or dissolved complex organic wastes and renewable biomass.

Microbial fuel cells (MFCs) have emerged in recent years as a promising yet challenging technology.

Key words: Microbial fuel cells (MFC), biosensor, wastewater treatment



Zahari Zarkov, Ludmil Stoyanov, Hristiyan Kanchev, Valentin Milenov, Vladimir Lazarov

Abstract: The purpose of the work is to compare the characteristics of photovoltaic (PV) generators built with panels manufactured by different technologies and operating in real conditions. The paper shows results from an experimental study of PV systems with different module types (mono-Si, poly-Si, μc-Si, CIGS and CdTe). The experiment was carried out at a research platform for PV systems developed by the authors, built and located at an experimental site near the Technical University of Sofia. Comparisons are made between the performances of the studied PV generators for the same operating conditions. Some differences of the operation of the PV systems in sun tracking mode and in fixed angle mode are also shown.

Keywords: PV systems, photovoltaic modules, comparison


CHARACTERISTICS AND EVALUATION OF THE sludge FROM Wastewater plant treatment station Kazanlak FOR USE IN PRACTICE

Svetla Marinova, Nikola Katidjotes,Viktor Kolchakov, Elena Zlatareva,Vera Petrova

Abstract: In recent years, are built and entered into operation a large number Wastewater plant treatment station (WWTP). In biological purification, purified water and sludge. Sludge accumulate around stations hamper their functioning and pollute the environment. In connection with EU requirements is necessary to seek ways to implement them in practice. An analysis and assessment of sludge in pulification station in Kazanlak, after storage , as required by the law - are studied chemical, agrochemical and microbiological parameters.The results establish that the sludges are biomass, rich in macro and micro- elements and can be used in practice.The problem is the microbiological indicators that do not meet the requirements of the legislation. It is necessary seek ways and methods for decontamination and sludge stabilization before  to utilization.

Keywords: sludge, recovery, characterization.



V. Hubenov, D. Denchev, I. Simeonov

Abstract. One of the most important factors in the process of anaerobic digestion (AD)  is the C/N ratio in the substrate. If it is too high, the nitrogen reduction will be a process-limiting factor. At too low levels a large quantity of NH3 will be formed, which is toxic for the microbial populations. Despite lots of examinations, the exact value of this ratio is still undetermined.

The aim of this study is to elucidate the influence of the C/N ratio on the metabolites, enzyme activity and biogas production during the anaerobic degradation of cattle manure.

The variations in the volatile fatty acids (VFAs) concentration, the activity of the enzymes - cellulases, proteases, lipases and amylases, as well as the biogas production were studied in a batch process at 35ºC during 14 days. The initial C/N ratio was 15:1, 20:1, 25:1 and 30:1.

The VFAs formation during the AD of cattle manure increased with changing the C/N ratio up to 25:1. The maximum concentration of these metabolites was 46 mg/L on day 7 from the beginning of cultivation. This value was 38 mg/L at the C/N ratio of 30:1. The produced biogas quantity was proportional to the C/N ratio and maximum also at 25:1. The rate of inclusion of VFAs in biogas production  increased continuously during the process and after 7 days it superseded the rate of VFAs formation from the substrate. As a result, their quantity in the bioreactor decreased. The activity of all studied enzymes was highest at the ratio of 25:1. The cellulases and amylases participate most actively in the substrate degradation.

The process of AD of cattle manure with biogas production runs with the highest rate at the initial C/N ratio of 25:1 ensuring an optimal quantity of metabolites and specific enzyme activity values reflecting the assimilation of cellulose, monosaccharides, proteins and lipids from the substrate.

Key words: anaerobic digestion, biogas, carbon/nitrogen ratio, cattle manure